A video effects generator is a device that receives at least two input video signals and enables an operator to select between the input signals alternately within the time of one field in generating a final program video signal.
The use of video effects generators in the professional studio environment is well known. Such effects generators provide for generation of a wide range of effects from simple wipes and fades, through keying a foreground scene represented by one signal into a background scene represented by another signal, to zooming, tumbling and rotating the foreground scene within the background scene.
Video effects generators suitable for use in a less sophisticated environment than the professional television studio, are currently available, but they are rather limited in the range of effects that they can provide.